1. Field of the Invention
The present invention relates to a camcorder, and more particularly to an object tracking apparatus and method of a camcorder, which uses infra-red for auto-focusing, wherein the movement of objects is detected by using infra-red incident upon light receiving member from objects and thus moving objects can be automatically tracked and photographed.
2. Description of Prior Art
Recent development of sophisticated technologies has set a tendency of making a camcorder light-weighted, miniaturized and automated.
Specifically conspicuous is the rapidly-progressing development of object tracking function which can automatically track and photograph objects and of auto-focusing function which can perform the focus automatically, which is accelerated by the need that the development of auto-focusing function and object tracking function can be effectively utilized by camcorder, because, in the days when the popularization of camcorders is on the increase, the user himself absolutely needs said technologies when he wishes to photograph.
Accordingly, in Japanese laid open patent application No. Sho 62(1987)-208783 entitled, "Automatic Tracking Video Camera", a technique is disclosed wherein the infra-red received from objects is photo-electrically (converted) central position of objects is detected from the photo-electrically (converted) electrical signal and camera direction is controlled as opposed to the central position of detected objects.
However, said Japanese laid open patent application No. Sho 62-208783 has a disadvantage of complicating the apparatus by detecting the central position of the objects after infra-red is received from the objects and converted to electrical signals, which is not proper to suit the current trend of giving importance to miniaturizing the camcorder because voluminous size of equipment causes one of the reason to increase the price of a camcorder.
Furthermore, separate apparatuses are needed to equip auto-focusing function, thus causing inevitable increase of unit price and bulkiness of the apparatus.
In other words, separate auto-focusing apparatus is needed, as depicted in FIG. 1 and FIG. 2, in order to equip auto-focusing and object tracking function.
According to FIG. 1, auto-focusing apparatus 100 is mounted under the lens 10 of a camcorder and on the front of the main body 20.
Said auto-focusing apparatus 100 comprises a light emitter 1, a light receiver 2 for receiving incident infra-red reflected upon objects after emitted from said light emitter 1, and a controller (not shown) wherein a distance between a camcorder and an object is calculated by the time difference between the time infra-red is emitted from said light emitter i and the time infra-red is received from light receiver 2, and then lens 10 is driven by the calculated value for performing focusing.
In this location, a light receiver 2 comprises a light receiving lens 3 for collecting incident infra-red and a photoelectric conversion element of a photo sensor (such as photo diode) 4 for converting the light collected from said light receiving lens 3 to electrical signal.
In FIG. 2 a photo sensor 4 of said photo electric conversion element is enlarged for illustration.
In other words, the infra-red collected at light receiving lens 3 of light receiver 2 is detected by two photo sensors 4 as depicted in FIG. 2, converted to electrical signal and is outputted to a controller (not shown), which, by utilizing the infra-red received by said photo sensor 4, calculates the distance between a camera and an object for performing the focusing.
Accordingly, in order to equip auto-focusing function and automatic object tracking function for a camcorder, an auto-focusing apparatus and an automatic object tracking apparatus have been conventionally needed, thereby causing the problem of making a camcorder bulky, which is a reverse trend of miniaturizing and lightening the camcorder.